The end use of a fence is an important consideration when designing same. In the case of barrier fences, such as are used to surround construction sites and sporting events, important end use considerations to be accounted for in the design include high visibility, sag resistance, resistance to being blow down, portability and ease in handling and installing. A barrier fence, such as disclosed in U.S. Pat. No. 4,671,495, includes slats that are attached to posts and rotate partially around the posts, or in the U.S. Pat. No. 3,426,536, the fence is built from pliable strips and posts, with the strips alternately plaited through the posts perpendicular to the ground. These fences are designed to be durable, yet neither is practical because they are not portable, flexible or easily installed.
Fences have been used for snow control purposes, such as U.S. Pat. No. 514,999 which describes a metal snow fence of broad metal bands interwoven with a metal thread and U.S. Pat. No. 3,672,638 describes a snow fence made from a wire fabric containing warp and weft wires.
Assignees U.S. patent application Ser. No. 401,993 entitled Silt Control Fabric, filed Sep. 1, 1989, discloses a woven silt control fabric using synthetic yarns to prevent soil run-off. Woven silt control fabrics are generally designed to have water flow capacity of about 20 of above gallons per minute per square foot of fabric (gal/min/fr.sup.2), while retaining soil particles greater than 20 apparent opening size (AOS), also termed equivalent opening size (EOS). (Apparent opening size numbers correspond to U.S. sieve size; for example, a 20 AOS equals a 20 sieve and a 30 AOS equals a 30, sieve.) For example, two woven silt control fabrics sold by Amoco Fabrics & Fibers Company, and designed at Number 1380 and Number 2125 in a brochure entitled "WOVEN FABRIC SELECTION GUIDE," have water flow capacities, also called permitivities, of 30 and 15 gal/min/ft.sup.2, respectively, while having an AOS of between 30 to 50 and between 20 to 30, respectively.
In an attempt to substitute materials for fencing which are not as bulky as weighty as the aforementioned barrier and snow fences, fencing products made from fibrous materials, such as nylon, polyester, cotton, and the like, have been used for crown control, snow fending, and to control soil erosion. U.S. Pat. No. 4,636,428 is directed to a knit fencing product finished with a polymeric coating adhered to the surface and impregnated into each strand, with a goal of rendering the fabric resistant to abrasion and ultraviolet light.
Plastic fences for commercial and industrial applications are available from, Tensar Polytechnologies, Inc. Tensar sells: a Banded Fence which has three bands in the warp direction, at the top, middle, and bottom with a substrate therebetween; a Safety Barrier sheet with oblong apertures in the warp direction; a Safety Grid with narrow vertical and horizontal strips with square openings; and Tensar UX3100 and UX3200 snow fencing which appear to be similar in many respects to those previously described. A Raschel knit barrier fence with oblong openings in the warp direction is available from Weathashade Corporation.
Other patents that may be of interest in connection with the present invention are Assignee's U.S. Pat. No. 3,871,910 directed to a leno polypropylene fabric having a polypropylene copolymer print band, which is useful for making fruit and vegetable bags and Assignee's U.S. Pat. No. 4,557,958, directed to a fabric suitable for use as a cotton bale cover or bag fabric comprising a woven substrate with a series of stripes of a thermoplastic resin fused thereto.
Neither discloses or suggests fencing. The aforementioned references do not disclose the present invention nor do they address the problems solved by the instant invention, such as providing a highly visible and durable fence: (i) with superior sag resistance which substantially resists stretching during high winds and inclement weather, while being sufficiently stretchable to be pulled tautly or slightly stretched during installation for superior visibility and appearance; and (ii) with stripes having improved resistance to ripping and tearing, thereby enhancing the useful life of such fence.
It therefore would be desirable to provide an improved fence having properties such as, easy to install, bright and highly visible, economical, made of a light weight material which is ultraviolet stabilized, will not unravel or mildew, durable and resilient, light weight for easy storage and handling, flexible at high and low temperatures, and long lasting.
It is an object of the present invention to provide an improved barrier fence.
It is an object of the present invention to provide a highly visible fence with a superior appearance, including, for example, a reflective material, and light weight, easy to erect, dismantle and store.
It is also an object of the present invention to provide a fence with superior sag resistance and enhanced dimensional stability during use.
It is also an object of the present invention to provide a fence which is made of a material capable of being recycled.
These and other objects of the present invention will become more apparent from a consideration of the following description and drawings.